1. Shape beef into 12 1-inch patties.
2. Place on a microwave-safe plated lined with paper towel. Cover and microwave on high for 1- minute or until meat is cooked through.
3. Cut each slice of cheese into fourths and set aside.
4. Using a 1-in round cookie cutter, cut out 6 circles from each slice of bread.
5. Spread half the bread circles with the dressing.
6. Layer with burgers, cheese, onion, pickles and tomatoes.
7. Top with remaining bread circles and secure with toothpicks.